Micro laser plasma thrusters for small satellites

The micro laser plasma thruster ((mu) LPT) is an efficient, long- life, low-thrust pulsed rocket engine which uses a high-brightness semiconductor or glass fiber laser as a source of energy. It uses a simple, low-voltage semiconductor switch to drive the laser, resulting in zero off-state electrical power. Results are presented of the first experimental demonstration of uLPT's. We measured single impulses covering 5 orders of magnitude from 40 micro dyn-s [< 1 nano newton-s] to 2 dyn-s, specific impulse up to 1,800 seconds and coupling coefficients up to 25 dyne-s/J. Several target materials were studied. Initial applications are orientation and re-entry at end of life for micro- and nanosatellites. Anticipated lifetime output of the prototype engine now under development is about 5E7 dyn-s [500 newton-s], sufficient to re-enter a 5 kg LEO satellite.